Austrasia was a territory which formed the north-eastern section of the Merovingian Kingdom of the Franks during the 6th to 8th centuries. It was centred on the Meuse, Middle Rhine and the Moselle rivers, and was the original territory of the Franks, including both the so-called Salians and Rhineland Franks, which Clovis I conquered after first taking control of the bordering part of Roman Gaul, now northern France, which is sometimes described in this period as Neustria.

In 561, Austrasia became a separate kingdom within the Frankish kingdom and was ruled by Sigebert I. In the 7th and 8th centuries it was the powerbase from which the Carolingians, originally mayors of the palace of Austrasia, took over the rule of all Franks, all of Gaul, most of Germany, and northern Italy. After this period of unification, the now larger Frankish empire was once again divided between eastern and western sub-kingdoms, with the new version of the eastern kingdom eventually becoming the foundation of the Kingdom of Germany.